I have 16" long GT175 Gear Tracs mounted in front of the pockets on my 13' Revolution.
Although these tracks are disgustingly expensive, I have been very satisfied with them, I recommend them over the GT90 tracks, and I would choose them again, for the following reasons:
1. The GT175 tracks spread out the forces on them over a much wider area. The GT175 tracks have a line of screws on each side of the track, and thus spread out the force which rod holders and other equipment exert on the track between this line of screws. On the GT90 tracks, all the leverage which rod holders place on the track is exerted between the center of the track and the edge of the track, which is only 7/16" (11mm, for those more comfortable with the metric system). This puts a large amount of upward force on the bolts, and a large amount of downward force on the edge of the track. If you only intend to use your tracks for holding gear which won't have much stress on it during normal operation, such as the base for a fishfinder or GPS, the GT90 track will do fine. However, if you intend to use the track to mount rod holders, and particularly rod holders which are raised on extenders, the rod holders will routinely put a lot of stress on the track, and I suggest that you use GT175 tracks.
2. The GT175 tracks can be mounted with screws from the outside of the kayak. Before you decide where to mount gear tracks on a kayak, reach inside the kayak and feel the area on the inside of where you are thinking of mounting the tracks. Some kayaks have large flat areas both on top of and inside the gunwales, and it is easy to reach the areas inside the gunwales through hatches. It can be quite easy to mount gear tracks on such a kayak, and you may be able to use a solid threaded bar inside the gunwale. In other kayaks, it can be real difficult to reach the area inside the gunwales, and/or that area may have various obstacles to installing nuts inside the gunwale. For example, the 13' Revolution has narrow gunwales, the area inside the gunwale is narrow and arched, there are lumps inside the gunwales for cast in nuts, and the tips of the screws which hold down the mesh pockets stick into the area inside the gunwales. You should definitely not try to use a threaded bar inside the narrow arched gunwales of a Revolution, because the bar is likely to end up contacting the inside of the kayak only at its left front and right rear corner, or right front and left rear corner. Even if you use nuts and fender washers inside the gunwales, you are likely to need to bend the fender washers to fit the inside of the gunwales, and the backs of the nuts probably won't sit flat on the inside of the gunwales. A big advantage of the GT175 tracks is that you can mount them completely from the outside of the kayak. Position the track, drill a hole on each end of the track, and put screws into the holes. Then drill the rest of the holes and put screws into them. You're done. On the 13' Revolution, you won't be able to use two of the screw holes because they will end up positioned over grooves in the cockpit of the kayak. But the track will still be held down by plenty of screws.
